Various kinds of beverage containers with generic closures are known. These are widely used as keg vessels. In the majority of cases, keg vessels are made from metal and, where applicable, have rubber casings. At the top end, the keg vessels have a substantially cylindrical neck with an end opening. This opening is closed with a closure cap. The cap conventionally has a valve and a connection for a coupling element to a tap. The valve is connected to a tube that is located inside the vessel and that extends to the bottom region of the vessel. Overpressure in the keg vessel's interior presses the contents of the keg vessel up to the valve via this tube.
A number of different systems are known for connecting the closure cap to the neck. WO 2007/064277 A1, for example, shows an arrangement where the closure cap engages over the neck on the outside. A positive locking arrangement between circumferential grooves and corresponding collars locks the closure cap to the vessel's neck. In addition, a circumferential ring on the neck underneath the closure cap is necessary for the stabilization and handling of the vessel.
Additional vessel closures are made known, for example, in DE 101 38 365 A1, EP 0 915 283 B1, and DE 36 08 300 A1.
The prior art container closures are complex, costly, and difficult to clean. Additionally, to achieve stability, they require strengthening in the neck region. This strengthening enables them to absorb the sometimes high-pressure loads in the interior of the vessel.